1. Technical Field
The present invention relates to a printing apparatus, a printing method and a printed matter.
2. Related Art
An ink jet type printer is in wide use, which forms an image by ejecting ink. With regard to the ink jet type printer like this, a form of printing is also considered in which the metallic tone printing is performed by ejecting metallic ink and color ink onto a medium.
JP-A-2004-122505 discloses that a printed matter is provided which is printed in such a manner that at least one color of a print portion printed in multiple colors is determined as a latent image print portion and the latent image print portion has a greater amount of specular reflection than other print portions. JP-A-8-150800 discloses that a flat portion which specularly reflects light in a concave and convex pattern is formed, and in a case where this flat portion is color-copied, a copy of the flat portion appears in black. Furthermore, JP-A-10-850 discloses that color is printed on a metallic base, but the color does not cover the whole metallic base.
JP-A-2004-122496 discloses that glossiness is changed by controlling the degree to which droplets are integrated into one piece. JP-A-2011-37015 discloses that an amount of clear ink is adjusted based on an amount of color ink. JP-A-2004-1410 discloses that an amount of improved ink is adjusted based on an amount of color ink discharged.
A copy machine performs the copying by detecting color due to diffuse reflection light. The case is considered where an image is formed by ejecting the color ink onto a glittering layer such as a metallic layer. In the case where the color ink is not present on the glittering layer, most of incident light turns into specular reflection light and the copy machine may not detect the diffuse reflection light. As a result, a copy of this portion is in black. Furthermore, in the case where the image with a high light absorption rate is formed on the glittering layer, the amount of the diffuse reflection light is also small because the amount of reflection light is small, and a copy of this portion is also in near black color. On the other hand, in the case where the image with a low light absorption rate is formed on the glittering layer, the color copying of this portion is appropriately performed because the amount of the diffuse reflection light is large.
However, the case is considered where the performance of the color copying needs to be made difficult out of concern for security. That is, it is preferable that a printed matter which is difficult to copy is provided.